Kevin Foster (University of Oxford)
MolBio Seminar Series
University of Oxford
Kevin Foster studies the evolution of interactions between organisms, particularly microorganisms. After a first degree at Cambridge, Kevin moved to a Ph.D. in Sheffield under Francis Ratnieks studying the yellowjacket wasps with the goal of dissecting the conflict and cooperation that occurs within their societies. Next was the study of the slime mould Dictyostelium discoideum at Rice University in Texas. D. discoideum transitions from single cells to a multicellular life stage in which many cells die to form a stalk that hold the others aloft as spores. This resembles the self-sacrificial workers that help the queen in social insects and formed a bridge from the world of insects to that of microbes. After time in Berlin and Helsinki doing theory, Kevin started up a lab as a Bauer Fellow at the Harvard Center for Systems Biology where his focus moved to more conventional microbes, in particular bacteria and yeast. Three years ago, the lab moved to Oxford where Kevin is now Professor of Evolutionary Biology in the Department of Zoology.
The Genotypic View of Cooperation and Competition in Microbial Communities
Since Darwin, evolutionary biologists have been fascinated by cooperative behavior. Honeybee workers labor their whole life without reproducing, birds make alarm calls, and humans often help one another. One major group that remains relatively unexplored, however, is the microbes whose full spectrum of sociality only recently came to light. Microbes often live in large dense groups where one cell can strongly affect the survival and reproduction of others. But do microbes typically help or harm those around them and can we identify the factors that promote cooperation over competition? We study these questions using a diversity of systems, including computer simulations, pseudomonad bacteria and budding yeast. We find that single-genotype patches naturally emerge in microbial groups, which creates favorable conditions for cooperation within a particular genotype. Experimental evolution in bacteria shows that this process drives extremely strong natural selection for cooperative adaptations that can be understood at the molecular scale. Moreover, some microbes actively adjust both genotypic assortment and investment into social traits in a way that promotes cooperation within a genotype. However, our work on interactions between different microbial genotypes suggests that, here, the evolution of competitive phenotypes is more likely than cooperation. This leads us to a simple model – the genotypic view – that predicts microbes will evolve to help their own genotype but harm most other strains and species that they meet.
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